CN118163944A - Bionic dragonfly flapping wing aircraft - Google Patents

Abstract

The invention discloses a bionic dragonfly flapping-wing aircraft, belonging to the technical field of aircraft, and comprising: a base support; a front flapping wing, a rear flapping wing, a front flapping device, and a rear flapping device, wherein: the front and rear flapping devices have the same structure and are symmetrically arranged at the front and rear ends of the base support; the flapping device comprises: a motor, a transmission flapping mechanism and a steering mechanism; the transmission flapping mechanism is a space crank block mechanism; the steering mechanism can control the flapping wing to perform variable sweep angle motion. The front and rear transmission flapping mechanisms are respectively controlled by two motors to control the flapping phase difference and flapping frequency between the front flapping wing and the rear flapping wing to complete the pitching motion, and the aircraft can complete the yaw or rapid sharp turn motion by controlling the front and rear steering mechanisms. If the front and rear steering mechanisms continuously reciprocate, the front flapping wing and the rear flapping wing can complete the up and down flapping motion of the front and rear sweep in space, and the real flight situation of the dragonfly is well simulated, achieving the bionic effect.

Description

Bionic dragonfly flapping-wing aircraft

Technical Field

The invention belongs to the technical field of aircraft, and in particular relates to a bionic dragonfly flapping-wing aircraft.

Background technique

A flapping-wing aircraft is an aircraft designed based on bionics that imitates the flight posture of bats, birds or insects. It has the advantages of high flight efficiency, good concealment, strong maneuverability, and the ability to flexibly change flight states. Compared with the two traditional flight modes of fixed-wing and rotary-wing aircraft, it can quickly achieve difficult movements such as sharp turns and dives that are difficult to achieve with traditional flight modes, making it more advantageous when flying in a narrow space. Moreover, under low Reynolds number conditions, flapping-wing flight can achieve more efficient aerodynamic efficiency and energy utilization than traditional flight modes, which also makes flapping-wing aircraft have broad application prospects in military and civilian fields.

At present, bionic flapping-wing aircraft generally use typical mechanisms such as single crank double rocker, crank slider, crank slide, double crank double rocker, and space crank connecting rod as their flapping mechanism, which can generally only achieve single-stage up and down flapping, and the flapping wings of most flapping-wing aircraft have low freedom in space, which leads to poor aerodynamic performance of flapping-wing aircraft and insufficient lift provided by flapping wings. In addition, the control of flapping-wing aircraft mainly depends on the tail wing, such as vertical tail wing, V-wing, and bird-like tail wing, and the control of its tail wing is usually relatively poor, and the feedback time is long and it is impossible to adjust the flight attitude of the aircraft in time.

Summary of the invention

The purpose of the present invention is to solve the problems of poor flight control effect and poor aerodynamic performance caused by low freedom of flapping wing space in most of the current flapping-wing aircraft, and to provide a bionic dragonfly flapping-wing aircraft based on the flight characteristics of dragonflies and aerodynamic theory.

A bionic dragonfly flapping-wing aircraft comprises: a base support 1, two front flapping wings 2, two rear flapping wings 3, a front flapping-wing device and a rear flapping-wing device, wherein the front flapping-wing device and the rear flapping-wing device have the same structure and are symmetrically arranged at the front and rear ends of the base support 1;

The front flapping wing device comprises: a front main motor 411, a left front transmission flapping mechanism 60, a right front transmission flapping mechanism 61, and a front steering mechanism 8; the front steering mechanism 8 comprises: a left front steering mechanism 80 and a right front steering mechanism 82, and the left front steering mechanism 80 and the right front steering mechanism 82 have the same structure;

The left front transmission flapping mechanism comprises: a left front output gear 615, a left front movable ball head 600, a left front crankshaft 601, a left front wing root connecting rod 602, and a left front wing root rotating block 603;

The bottom plate bracket 1 is provided with a crankshaft frame, and both ends of the left front crankshaft 601 are axially connected to the crankshaft frame of the bottom plate bracket 1; the left front output gear 615 is fixedly connected to the left front crankshaft 601, the left front movable ball head 600 is fixed to the middle section of the left front crankshaft 601, one end of the left front wing root connecting rod 602 is provided with a ball head sleeve, and the ball head sleeve of the left front wing root connecting rod 602 is axially connected to the left front crankshaft 601 through the left front movable ball head 600; the middle part of the left front wing root connecting rod 602 is slidably connected to the left front wing root rotating block 603, and the other end is connected to the front flapping wing 2; the left front wing root rotating block 603 is axially connected to the bottom plate bracket 1;

The left front output gear 615 and the right front output gear 614 are meshed with each other, and the front main motor 411 provides power input thereto.

The left front steering mechanism 80 comprises: a left front steering motor 802, a left front threaded rotating column 805, a left front sliding block 806, a left front linear guide rail 808, and a left front ball head support 807; the left front threaded rotating column 805, the left front sliding block 806, and the left front linear guide rail 808 form a lead screw structure, the left front ball head support 807 is installed on the left front sliding block 806, and the left front ball head support 807 is provided with a universal ball, which is connected to the left front wing root rotating block 603;

The left front motor support 801 and the left front linear guide 808 are fixedly connected to the base plate bracket 1, and the two ends of the left front threaded column 805 are axially connected to the corresponding brackets of the base plate bracket; the left front threaded column 805, the left front slider 806 and the left front linear guide 808 form a screw structure, the left front ball head support 807 is installed on the left front slider 806, and the left front ball head support 807 is provided with a universal ball, which is connected to the ball head sleeve of the left front wing root rotating block 603; the left front steering motor 802 is installed on the left front motor bracket, the left front steering pinion 803 is fixedly connected to the output shaft of the left front steering motor 802, the left front steering gear 804 is fixedly connected to the left front threaded column 805, and the left front steering pinion 803 and the left front steering gear 804 are meshed with each other.

The left front transmission flapping mechanism is provided with a left front elastic reset mechanism 10, which limits the left front wing root connecting rod 602 during movement and resets it after movement; the right front elastic reset mechanism 11 of the right front transmission flapping mechanism is the same as the left front elastic reset mechanism 10;

The crank of the left front crankshaft 60 of the left front elastic reset mechanism 10 is provided with a spring Ⅰ10a, a spring Ⅱ10b, a movable rotating piece Ⅰ10c, and a movable rotating piece Ⅱ10d. The movable rotating piece Ⅰ10c and the movable rotating piece Ⅱ10d are axially connected through the middle section of the left front crankshaft 601 and are fixed on the brackets on both sides of the ball head cover of the left front wing root connecting rod 602. The central apertures of the movable rotating piece Ⅰ10c and the movable rotating piece Ⅱ10d are larger than the diameter of the middle section of the left front crankshaft 601. The spring Ⅰ10a passes through the middle section of the left front crankshaft 601 and is arranged between the movable rotating piece Ⅰ10c and the front support platform of the left front crankshaft 601. The spring Ⅱ10b passes through the middle section of the left front crankshaft 601 and is arranged between the movable rotating piece Ⅰ10d and the rear support platform of the left front crankshaft 601. The spring Ⅰ10a and the spring Ⅱ10b are both in a compressed state.

The front flapping wing device is provided with a front reduction transmission mechanism 4, which includes: a front reduction transmission mechanism bracket 410, a main motor pinion 412, and a double-layer composite gear 413. The front reduction transmission bracket 410 is fixed to the bottom plate bracket 1 by screws, and the front main motor 411 is fixed to the rear motor mounting frame of the front reduction transmission bracket 410 by screws;

The axis of the left front output gear 615 is provided with a prismatic opening, and the left front crankshaft 601 is provided with a prism matching the prismatic opening. The left front crankshaft 601 is the same as the right front crankshaft 611. When the right front output gear 614 and the left front output gear 615 overlap, the edges of their prismatic openings intersect with each other, and the included angle is equal to 1/2 of the included angle between two adjacent teeth on the gear.

The left front output gear 615 and the right front output gear 614 are meshed with each other and fixed on the front gear mounting frame of the front reduction transmission bracket 410, wherein the right front output gear 614 is meshed with the small gear of the double-layer composite gear 413; the large gear of the double-layer composite gear 413 is meshed with the front main motor small gear 412, and the main motor small gear 412 is fixedly connected to the shaft of the front main motor 411;

The ball head cover of the left front wing root connecting rod 602 is connected to the middle section shaft of the left front crankshaft 601 through the left front movable ball head 600, and the left front movable ball head 600 and the left front crankshaft 601 are fixedly connected with variable position.

The present invention provides a bionic dragonfly flapping-wing aircraft, which belongs to the technical field of aircraft, and comprises: a base support; a front flapping wing, a rear flapping wing, a front flapping device, and a rear flapping device, wherein: the front and rear flapping devices have the same structure and are symmetrically arranged at the front and rear ends of the base support; the flapping device comprises: a motor, a transmission flapping mechanism and a steering mechanism; the transmission flapping mechanism is a space crank block mechanism; the steering mechanism can control the flapping wing to perform variable sweep angle motion. The front and rear transmission flapping mechanisms are respectively controlled by two motors to control the flapping phase difference and flapping frequency between the front flapping wing and the rear flapping wing to complete the pitching motion, and the aircraft can complete the yaw or rapid sharp turn motion by controlling the front and rear steering mechanisms. If the front and rear steering mechanisms continuously reciprocate, the front flapping wing and the rear flapping wing can complete the up and down flapping motion of the front and rear sweep in space, and the real flight situation of the dragonfly is well simulated, and the bionic effect is achieved.

In summary, compared with the prior art, the present invention has the following beneficial effects and advantages:

The flapping-wing aircraft simulates the flapping frequency and multi-degree-of-freedom motion of dragonfly wings in reality. It is a new type of bionic dragonfly flapping-wing aircraft proposed based on the flight characteristics of dragonflies and aerodynamic theory. Since the driving sources of the front and rear transmission mechanisms of the flapping-wing aircraft are different, the flapping phase difference and flapping frequency between the front and rear flapping wings can be controlled to complete the pitching motion. The front and rear steering mechanisms can enable the aircraft to complete yaw or rapid sharp turns. If the front and rear steering mechanisms continuously reciprocate, the front and rear flapping wings can complete the forward and backward sweeping up and down flapping in space, and they can be passively twisted within a certain range during the flapping wing motion, which can better simulate the real flight movements of dragonflies (pitch, yaw, dive, sharp turns, etc.), and achieve better bionic effects.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the overall structure of the bionic dragonfly flapping-wing aircraft of the present invention;

FIG2 is a schematic diagram of the overall structure of the front flapping device and the rear flapping device of the bionic dragonfly flapping-wing aircraft of the present invention;

3 is a schematic diagram of the specific position structure of the upper support seat and the installation positioning holes of the bottom plate bracket of the bionic dragonfly flapping-wing aircraft of the present invention;

FIG4 is a schematic diagram of the flapping-wing structure of the bionic dragonfly flapping-wing aircraft of the present invention;

FIG5 is a schematic diagram of the exploded structure of the front reduction transmission mechanism of the bionic dragonfly flapping-wing aircraft of the present invention;

6 is a schematic diagram of the specific structure of the square-hole gear in the front reduction transmission mechanism and the left front transmission flapping mechanism of the bionic dragonfly flapping-wing aircraft of the present invention;

7 is a schematic diagram of the overall structure of the front flapping device of the bionic dragonfly flapping-wing aircraft of the present invention;

8 is a schematic diagram of the specific structure of the wing root connecting rod of the bionic dragonfly flapping-wing aircraft of the present invention and its connection with the flapping wing;

9 is a schematic diagram of the exploded structure of the elastic mechanism at the root of the wing root connecting rod of the bionic dragonfly flapping-wing aircraft of the present invention;

10 is a schematic diagram of the specific structure of the front transmission flapping mechanism of the bionic dragonfly flapping-wing aircraft of the present invention;

11 is a schematic diagram of the specific structure of the steering mechanism of the bionic dragonfly flapping-wing aircraft of the present invention;

FIG12 is a schematic diagram of the bionic dragonfly flapping-wing aircraft of the present invention in a gliding or diving state;

FIG13 is a schematic diagram of a bionic dragonfly flapping-wing aircraft in a small yaw state according to the present invention;

FIG. 14 is a schematic diagram of the bionic dragonfly flapping-wing aircraft of the present invention in a state of a sharp turn.

In the attached picture:

1. Bottom plate bracket;

2. 2 front flapping wings; 21. Left front flapping wing; 22. Right front flapping wing; 210. Left front flapping wing wing mold; 211. Left front flapping wing wing vein; 212. Left front flapping wing connector; 213. Top wire;

3.2 rear flapping wings; 31. Left rear flapping wing; 32. Right rear flapping wing;

4. Front reduction transmission mechanism; 410. Front reduction transmission bracket; 411. Front main motor; 412. Front main motor pinion; 413. Front double-layer compound gear;

6. Front transmission flapping mechanism; 60. Left front transmission flapping mechanism; 600. Left front movable ball head; 601. Left front crankshaft; 602. Left front wing root connecting rod; 603. Left front wing root rotating block; 61. Right front transmission flapping mechanism; 610. Right front movable ball head; 611. Right front crankshaft; 612. Right front wing root connecting rod; 613. Right front wing root rotating block; 614. Right front output gear; 615. Left front output gear;

8. Front steering mechanism; 80. Left front steering mechanism; 801. Left front steering motor bracket; 802. Left front steering motor; 803. Left front steering pinion; 804. Left front steering gear; 805. Left front threaded column; 806. Left front slider; 807. Left front ball head support; 808. Left front linear guide; 82. Right front steering mechanism;

10. Left front elastic reset mechanism; 10a. Spring Ⅰ; 10b. Spring Ⅱ; 10c. Movable rotating plate Ⅰ; 10d. Movable rotating plate Ⅱ;

11.Right front elastic return mechanism.

Detailed ways

In order to make the above-mentioned objects, advantages and features of the present invention more clearly understood, the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific implementation methods of the present invention. It should be noted that the embodiments described below are only a part of all the embodiments of the present invention, not all the embodiments.

In order to make the bionic dragonfly flapping-wing aircraft in the present invention have a better bionic effect, the flapping frequency and multi-degree-of-freedom movement mode of the dragonfly wings in reality are simulated. The front and rear transmission mechanisms of the flapping-wing aircraft have different driving sources, so that the flapping phase difference and flapping frequency between the front and rear flapping wings can be controlled to complete the pitching motion. The front and rear steering mechanisms can enable the aircraft to complete yaw or rapid sharp turn motion. If the front and rear steering mechanisms continuously reciprocate, the front and rear flapping wings can complete the forward and backward sweeping up and down flapping motion in space and can passively twist within a certain range during the flapping wing motion, thereby better simulating the real flight movements of the dragonfly (pitch, yaw, dive, sharp turn, etc.) and achieving a better bionic effect.

The bionic dragonfly flapping-wing aircraft of the present invention comprises: a bottom plate support 1, two front flapping wings 2, two rear flapping wings 3, a front flapping-wing device and a rear flapping-wing device, wherein:

The bottom plate bracket 1 is made of a polymer composite material with high specific strength and specific stiffness, and has a plurality of support seats and installation positioning holes at the front and rear ends. The front flapping wing device and the rear flapping wing device have the same structure and are symmetrically arranged at the front and rear ends of the bottom plate bracket 1;

The two front flapping wings 2 and the two rear flapping wings 3 are basically the same in structure. The two front flapping wings 2 include a left front flapping wing 21 and a right front flapping wing 22. The two rear flapping wings 3 include a left rear flapping wing 31 and a right front flapping wing 32. Taking the left front flapping wing 21 as an example, its wing vein structure 211 is bionic designed with reference to the wing vein structure of a real dragonfly and its material is carbon fiber. The wing membrane 210 is made of a high-elastic polyester film wrapped on the upper and lower surfaces of the wing vein 211. The flapping wing connector 212 and the wing vein structure 211 are an integrated structure or fixedly connected.

The front flapping wing device comprises: a front main motor 411, a front reduction transmission mechanism 4, a front transmission flapping mechanism 6, and a front steering mechanism 8, wherein the front transmission flapping mechanism 6 comprises a left front transmission flapping mechanism 60 and a right front transmission flapping mechanism 61; the front steering mechanism 8 comprises: a left front steering mechanism 80 and a right front steering mechanism 82, and the left front steering mechanism 80 and the right front steering mechanism 82 have the same structure;

The front reduction transmission mechanism 4 includes: a front reduction transmission mechanism bracket 410, a main motor pinion 412, and a double-layer composite gear 413. The front reduction transmission bracket 410 is fixed to the bottom plate bracket 1 by screws, and the front main motor 411 is fixed to the rear motor mounting frame of the front reduction transmission bracket 410 by screws; the main motor pinion 412 is fixedly connected to the output shaft of the front main motor 411; the double-layer composite gear 413 is fixed to the front gear mounting frame of the front reduction transmission bracket 410 by pins; the main motor pinion 412 and the larger gear of the double-layer composite gear 413 are meshed with each other;

The left front transmission flapping mechanism 60 comprises: a left front output gear 615, a left front movable ball head 600, a left front crankshaft 601, a left front wing root connecting rod 602, and a left front wing root rotating block 603;

The right front transmission flapping mechanism 61 comprises: a right front output gear 614, a right front movable ball head 610, a right front crankshaft 611, a right front wing root connecting rod 612, and a right front wing root rotating block 613;

The left front output gear 615 and the right front output gear 614 mesh with each other and are both fixed to the front gear mounting frame of the front reduction transmission bracket 410 by pins, wherein the right front output gear 614 meshes with the smaller gear of the double-layer compound gear 413; thus forming a two-stage reduction transmission mechanism, the front main motor 411 inputs low-speed and high-torque power to the front transmission flapping mechanism 6 through the reduction mechanism;

The bottom plate bracket 1 is provided with a crankshaft frame, one end of the left front crankshaft 601 is axially connected to the crankshaft frame of the bottom plate bracket 1; the other end thereof is fixedly connected to the boss square hole of the left front output gear 615, the left front movable ball head 600 is fixed to the middle section of the left front crankshaft 601, one end of the left front wing root connecting rod 602 is provided with a ball head sleeve, and the ball head sleeve of the left front wing root connecting rod 602 is axially connected to the left front crankshaft 601 through the left front movable ball head 600; the middle part of the left front wing root connecting rod 602 is slidably connected to the left front wing root rotating block 603, and the other end is connected to the left front flapping wing 21; the left front wing root rotating block 603 is axially connected to the bottom plate bracket 1;

The right front transmission flapping mechanism 61 and the left front transmission flapping mechanism 60 are consistent in mechanism distribution.

The left front steering mechanism 80 and the right front steering mechanism 82 of the bionic dragonfly flapping-wing aircraft of the present invention are symmetrically arranged at the two ends of the front transmission flapping mechanism 6, and the left front steering mechanism 80 comprises: a left front motor support 801, a left front steering motor 802, a left front steering pinion 803, a left front steering gear 804, a left front threaded rotating column 805, a left front sliding block 806, a left front ball head support 807, and a left front linear guide rail 808; the left front motor support 801 and the left front linear guide rail 808 are fixedly connected to the base plate bracket 1, and the two ends of the left front threaded rotating column 805 are axially connected to the corresponding brackets of the base plate bracket; the left front threaded rotating column 805, the left front sliding block 806 and the left front linear guide rail 808 form a screw structure, and the left front ball head support 807 is installed on the left front sliding block 806. The front ball head support 807 is provided with a universal ball, and the universal ball is connected to the ball head sleeve of the left front wing root rotating block 603; the left front steering motor 802 is installed on the left front motor bracket, the left front steering pinion 803 is fixedly connected to the output shaft of the left front steering motor 802, the left front steering gear 804 is fixedly connected to the left front threaded rotating column 805, and the left front steering pinion 803 and the left front steering gear 804 are meshed with each other; therefore, the left front steering mechanism uses the left front steering motor 802 as a driver; from the above, it can be seen that the left front steering mechanism 80 and the right front steering mechanism 82 can respectively drive (push or pull) the left front wing root connecting rod 602 and the right front wing root connecting rod 612 connected thereto to rotate forward or backward, thereby driving the two front flapping wings 2 to perform variable sweep angle movement to achieve the effect of controlling the flight direction.

The left front transmission flapping mechanism 60 of the bionic dragonfly flapping-wing aircraft of the present invention is provided with a left front elastic reset mechanism 10, which utilizes a part of the support structure of the left front crankshaft 601 and the left front wing root connecting rod 602, and adds a spring Ⅰ10a, a spring Ⅱ10b, a movable rotating plate Ⅰ10c, and a movable rotating plate Ⅱ10d on this basis. The movable rotating plate Ⅰ10c and the movable rotating plate Ⅱ10d pass through the middle section of the left front crankshaft 601 and are axially connected to the two side brackets of the ball head cover of the left front wing root connecting rod 602. The central aperture of the movable rotating plate Ⅰ10c and the movable rotating plate Ⅱ10d is larger than the diameter of the middle section of the left front crankshaft 601, which satisfies The necessary conditions for the left front wing root connecting rod 602 to rotate back and forth within a certain range and drive the flapping wing to change the sweep angle movement; the spring Ⅰ10a passes through the middle section of the left front crankshaft 601 and is arranged between the movable rotating plate Ⅰ10c and the front support platform of the left front crankshaft 601, and the spring Ⅱ10b passes through the middle section of the left front crankshaft 601 and is arranged between the movable rotating plate Ⅰ10d and the rear support platform of the left front crankshaft 601; the spring Ⅰ10a and spring Ⅱ10b are both in a compressed state, thereby forming an elastic reset mechanism that limits the left front wing root connecting rod 602 during movement and resets it after movement; the right front elastic reset mechanism 11 of the right front transmission flapping mechanism is the same as the left front elastic reset mechanism 10.

The right front transmission flapping mechanism 61 and the left front transmission flapping mechanism 60 of the bionic dragonfly flapping-wing aircraft of the present invention are consistent in structure division.

The axis of the left front output gear 615 is provided with a prism-shaped opening, and the left front crankshaft 601 is provided with a prism matching the prism-shaped opening. The left front crankshaft 601 is the same as the right front crankshaft 611; the angles of the prism-shaped openings of the left front output gear (615) and the right front output gear 614 are slightly different.

When the right front output gear 614 and the left front output gear 615 overlap, the edges of their prismatic openings intersect each other, and the included angle is equal to 1/2 of the included angle between two adjacent teeth on the gears; the other parts completely overlap. When the right front output gear 614 and the left front output gear 615 are meshed, their prismatic openings are symmetrical to each other.

To ensure the symmetrical synchronization of the movement of the right front crankshaft 611 and the left front crankshaft 601, during the gear manufacturing process, the square hole of the right front output gear 614 should be rotated in space by an angle corresponding to "1/2 tooth" compared with the square hole of the left front output gear 615, and when installed on the front reduction transmission bracket 410, the installation should be carried out according to the symmetry of the square holes.

The ball head cover of the left front wing root connecting rod 602 of the bionic dragonfly flapping-wing aircraft of the present invention is connected to the middle section shaft of the left front crankshaft 601 through the left front movable ball head 600, and the left front movable ball head 600 and the left front crankshaft 601 are fixedly connected with each other in a position changeable manner; by making the left front crankshaft 601 into a split and splicable structure and opening a hole on the left front wing root connecting rod 602, before each flight test, the movable ball head I is moved to a suitable position on the left front crankshaft 601 through the hole of the left front wing root connecting rod 602 and the movable ball head I is fixed to the designated position of the left front crankshaft 601 by using a top screw structure; this structure can be used to change the spacing between the front flapping wing and the rear flapping wing in the front-to-back direction before take-off, and when replacing flapping wings of different sizes, this method can avoid interference between the front flapping wing and the rear flapping wing during movement, so that the applicability of the flapping-wing device is stronger.

The left front flapping wing 21 of the bionic dragonfly flapping-wing aircraft of the present invention is inserted into the outer slot of the wing root connecting rod 602 through the left front flapping wing connector 212 and fixed through the top screw 213; the top screw and the number of threaded holes matched therewith are set according to the actual weight of the fuselage and the specific size of the flapping wing.

The mechanism motion process of the bionic dragonfly flapping-wing aircraft of the present invention is specifically as follows:

The front flapping-wing device and the rear flapping-wing device described in the flapping-wing aircraft have the same structure, so take the front flapping-wing device as an example: when working, the front main motor 411 with an outer rotor and a rear-output shaft generates power to drive the front main motor pinion 412 with a module of 0.5 and a number of teeth of 10 fixedly connected to it to rotate, and the front main motor pinion 412 drives the large teeth of the first two layers of composite gears 413 (the small gear has 20 teeth, the large gear has 100 teeth, and the module of both is 0.5) on the front reduction transmission bracket 410 to rotate, and the smaller gears of the first two layers of composite gears 413 drive the right front output gear 614 with a module of 0.5 and a number of teeth of 100 on the front reduction transmission bracket 410 to rotate, and the right front output gear 614 drives the left front output gear 615 with a module of 0.5 and a number of teeth of 100 also located on the bracket 410 to rotate. At this time, the front main motor 411 transmits the low-torque high-torque power to the left front flapping mechanism 60 and the right front flapping mechanism 61 through the reduction mechanism. Because the left front flapping mechanism 60 and the right front flapping mechanism 61 have symmetrical synchronization in their movements, the description will be continued by taking the movement of the left front flapping mechanism 60 as an example: one end of the left front crankshaft 601 is axially connected to the corresponding support of the bottom plate bracket 1, and the other end is fixedly connected to the left front output gear 615; therefore, the left front output gear 615 transmits the power to the left front crankshaft 601 fixedly connected thereto through the square hole on the boss. The left front crankshaft 601 drives the left front wing root connecting rod 602 and the left front wing root rotating block 603 to rotate around the left front ball head support 807. During this process, a certain relative sliding will occur between the left front wing root connecting rod 602 and the left front wing root rotating block 603. The root of the left front wing root connecting rod 602 is provided with an elastic reset mechanism 10, which always keeps it in a restored state and plays a certain limiting role. The rotation of the left front wing root connecting rod 602 will drive the left flapping wing 21 connected thereto to flap up and down. Thereby, the up and down flapping of the left front flapping wing 21 can be realized. During flight, the left front steering motor 802 in the left front steering mechanism 80 is controlled to rotate forward and reverse to drive the left front slider 806 in the screw structure to move forward or backward along the left front linear guide rail 808, and then the left front ball head support 807 located on the left front slider 806 drives (pushes or pulls) the left front wing root rotating block 603 connected thereto and the left front wing root connecting rod 602 slidably connected to the left front wing root rotating block 603 to rotate forward or backward. During this process, relative sliding will also occur between the left front wing root connecting rod and the left front wing root rotating block.

The left front flapping wing 21 and the right front flapping wing 22 will both produce a certain extension and retraction movement in the expansion direction during the flapping process. This feature can be used to provide greater lift for the flapping wings so that the flapping-wing aircraft has better aerodynamic performance. It is only necessary to control the forward and reverse rotation of the front main motor 411 to make the wings extend when flapping downward and contract when flapping upward; this will reduce the resistance of the flapping wings when flapping upward, thereby increasing the overall lift generated by the flapping wings.

Based on bionics, the flapping frequency of the bionic dragonfly flapping-wing aircraft is designed to be 20-25Hz, the reduction ratio of the reduction gear set is set to 50:1, and the power supply mode of 3S (11.1V) lithium battery and the front main motor 411 with a value of 5400-6700kv are selected. When the power supply system has sufficient power, the theoretical flapping frequency can be met.

In summary, the flapping-wing aircraft simulates the flapping frequency and multi-degree-of-freedom motion mode of dragonfly wings in reality, and is a new type of bionic dragonfly flapping-wing aircraft proposed based on dragonfly flight characteristics and aerodynamic theory. The flapping-wing aircraft can realize multiple motion modes; due to the different driving sources of the front and rear transmission mechanisms of the flapping-wing aircraft, the flapping phase difference and flapping frequency between the front and rear flapping wings can be controlled to complete the pitching motion. The wings of the bionic dragonfly flapping-wing aircraft have no phase difference or the phase difference is not large and can achieve the gliding or diving state shown in Figure 12 when they are not flapping; the flapping wings will passively deform when flapping up and down to generate a propulsion force perpendicular to the leading edge of the flapping wings, because the front and rear steering mechanisms can independently control the flapping wings connected to them to perform variable sweep angle motion; therefore, the sweep angle of the two front flapping wings is adjusted by the front steering mechanism to generate a certain yaw torque so that the aircraft can complete the small-amplitude yaw motion shown in Figure 13; similarly, the front and rear two pairs of flapping wings are controlled to change the sweep angle motion to generate a larger yaw torque, and the large-amplitude sharp turn motion shown in Figure 14 can be completed. When the wings flap, if the front and rear steering mechanisms continuously reciprocate, the front and rear flapping wings can complete the up and down flapping of forward and backward sweeping in space, and passive twisting can occur within a certain range during the flapping movement. When the left and right steering mechanisms continuously reciprocate asymmetrically, the flapping-wing aircraft can also generate a yaw moment. The wingtip motion trajectory of the flapping-wing aircraft can realize an "8-shaped" or "elliptical" trajectory, and the real flight movements of dragonflies (pitch, yaw, dive, sharp turn, etc.) can be well simulated, achieving a better bionic effect.

Since the innovation of the present invention mainly lies in the innovation of the structure of the flapping-wing aircraft itself, the flapping-wing aircraft control system is not included in the present invention. Of course, if the technology permits, a visual system can be added to process the information obtained by the visual system and then feed it back to the control system; while recording the surrounding environment in real time, obstacles that appear can be avoided, thereby achieving perfect closed-loop control.

Claims (9)

1. A bionic dragonfly flapping-wing aircraft, comprising: a base support (1), two front flapping wings (2), two rear flapping wings (3), a front flapping-wing device and a rear flapping-wing device, wherein the front flapping-wing device and the rear flapping-wing device have the same structure and are symmetrically arranged at the front and rear ends of the base support (1); The front flapping wing device comprises: a front main motor (411), a left front transmission flapping mechanism (60), a right front transmission flapping mechanism (61), and a front steering mechanism (8); the front steering mechanism (8) comprises: a left front steering mechanism (80) and a right front steering mechanism (82); the left front transmission flapping mechanism (60) and the right front transmission flapping mechanism (61) are identical; and the left front steering mechanism (80) and the right front steering mechanism (82) are identical in structure; The left front transmission flapping mechanism (60) comprises: a left front output gear (615), a left front movable ball head (600), a left front crankshaft (601), a left front wing root connecting rod (602), and a left front wing root rotating block (603); The bottom plate bracket (1) is provided with a crankshaft frame, and both ends of the left front crankshaft (601) are axially connected to the crankshaft frame of the bottom plate bracket (1); the left front output gear (615) is fixedly connected to the left front crankshaft (601), the left front movable ball head (600) is fixed to the middle section of the left front crankshaft (601), one end of the left front wing root connecting rod (602) is provided with a ball head sleeve, and the ball head sleeve of the left front wing root connecting rod (602) is axially connected to the left front crankshaft (601) through the left front movable ball head (600); the middle part of the left front wing root connecting rod (602) is slidably connected to the left front wing root rotating block (603), and the other end is connected to the left front flapping wing (21); the left front wing root rotating block (603) is axially connected to the bottom plate bracket (1); The left front output gear (615) and the right front output gear (614) are meshed with each other, and the front main motor (411) inputs power to them. 2. The bionic dragonfly flapping-wing aircraft according to claim 1 is characterized in that: the left front steering mechanism (80) comprises: a left front steering motor (802), a left front threaded rotating column (805), a left front sliding block (806), a left front linear guide rail (808), and a left front ball head support (807); the left front threaded rotating column (805), the left front sliding block (806), and the left front linear guide rail (808) form a screw structure, the left front ball head support (807) is installed on the left front sliding block (806), and the left front ball head support (807) is provided with a universal ball, which is connected to the left front wing root rotating block (603). 3. The bionic dragonfly flapping-wing aircraft according to claim 2 is characterized in that: the left front motor support 801 and the left front linear guide rail (808) are fixedly connected to the base plate support (1), and the universal ball is connected to the ball head sleeve of the left front wing root rotating block (603); the left front steering motor (802) is installed on the left front motor support, the left front steering pinion (803) is fixedly connected to the output shaft of the left front steering motor (802), the left front steering gear (804) is fixedly connected to the left front threaded rotating column (805), and the left front steering pinion (803) and the left front steering gear (804) are meshed with each other. 4. The bionic dragonfly flapping-wing aircraft according to any one of claims 1 to 3 is characterized in that: the left front transmission flapping mechanism is provided with a left front elastic reset mechanism (10) to limit the left front wing root connecting rod (602) during movement and reset after movement; the right front transmission flapping mechanism is provided with a right front elastic reset mechanism (11), which is the same as the left front elastic reset mechanism (10). 5. The bionic dragonfly flapping-wing aircraft according to claim 4 is characterized in that: a spring I (10a), a spring II (10b), a movable rotating piece I (10c), and a movable rotating piece II (10d) are arranged on the crank of the left front crankshaft (60) of the left front elastic reset mechanism (10), the movable rotating piece I (10c) and the movable rotating piece II (10d) are axially connected through the middle section of the left front crankshaft (601), and are fixed on the two side brackets of the ball head cover of the left front wing root connecting rod (602), and the movable rotating piece I (10c) and the movable rotating piece II (10d) are axially connected through the middle section of the left front crankshaft (601), and are fixed on the two side brackets of the ball head cover of the left front wing root connecting rod (602). The central apertures of plate I (10c) and movable rotating plate II (10d) are larger than the diameter of the middle section of the left front crankshaft (601); spring I (10a) passes through the middle section of the left front crankshaft (601) and is arranged between movable rotating plate I (10c) and the front support platform of the left front crankshaft (601); spring II (10b) passes through the middle section of the left front crankshaft (601) and is arranged between movable rotating plate I (10d) and the rear support platform of the left front crankshaft (601); the spring I (10a) and spring II (10b) are both in a compressed state. 6. The bionic dragonfly flapping-wing aircraft according to claim 5 is characterized in that: the front flapping-wing device is provided with a front reduction transmission mechanism (4), which comprises: a front reduction transmission mechanism bracket (410), a main motor pinion (412), and a double-layer composite gear (413); the front reduction transmission bracket (410) is fixed to the bottom plate bracket (1) by screws, and the front main motor (411) is fixed to the rear motor mounting frame of the front reduction transmission bracket (410) by screws. 7. The bionic dragonfly flapping-wing aircraft according to claim 6 is characterized in that: the axis of the left front output gear (615) is provided with a prismatic opening, the left front crankshaft (601) is provided with a prism matching the prismatic opening, and the left front crankshaft (601) is the same as the right front crankshaft (611); when the right front output gear (614) and the left front output gear (615) overlap, the edges of their prismatic openings intersect with each other, and the angle between them is equal to 1/2 of the angle between two adjacent teeth on the gear. 8. The bionic dragonfly flapping-wing aircraft according to claim 7 is characterized in that: the left front output gear (615) and the right front output gear (614) are fixed on the front gear mounting frame of the front reduction transmission bracket (410), wherein the right front output gear (614) is meshed with the small gear of the double-layer composite gear (413); the large gear of the double-layer composite gear (413) is meshed with the small gear of the front main motor (412), and the small gear of the main motor (412) is fixedly connected to the shaft of the front main motor (411). 9. The bionic dragonfly flapping-wing aircraft according to claim 8 is characterized in that: the ball head sleeve of the left front wing root connecting rod (602) is connected to the middle section shaft of the left front crankshaft (601) through the left front movable ball head (600), and the left front movable ball head (600) and the left front crankshaft (601) are fixedly connected with variable position.